The present invention relates to a device for adjusting the clamping gap between folding jaws. A roller is used to open and close the folding jaws. This roller rides on a control cam track of an axially movable control cam. Movement of the cam changes the clamping gap.
A folding jaw cylinder of a folding apparatus of rotary printing presses which uses cam-controlled folding jaw shafts and resilient counter-jaws, is known from DE-GM 19 38 644. In this device, the controlled folding jaw spindles and the resilient counter-jaws are arranged on two separate cylinder body elements, which are rotatable in relation to each other. For setting the product thickness, both cylinder body elements are adjusted in respect to each other against the force of a spring by means of a wedge element.
In connection with this prior art folding jaw cylinder it is disadvantageous that it is necessary to adjust two cylinder body elements, which are expensive to produce, with respect to each other.
DE-OS 2755 361, describes a folding jaw cylinder of a rotary printing press. Control cams of the folding jaw can be adjusted in the circumferential direction of the folding jaw cylinder for setting an opening time of the folding jaws, and in the axial direction for changing the mode of operation.
DE-OS 21 03 946, discloses a folding jaw cylinder, wherein the folding jaw shafts are synchronized by means of gear wheels.
EP 0 095 605 A2, shows a control for a folding jaw of a jaw cylinder in the folding apparatus of rotary printing presses. Here, the angular position between the folding jaw and the associated roller lever can be changed.
DE-OS 27 55 361 describes a folding jaw cylinder of a rotary printing press. Control cams of the folding jaws can be adjusted in the circumferential direction of the folding jaw cylinder for setting an opening time of the folding jaws, and in the axial direction for changing the mode of operation.
DE-OS 21 03 946 discloses a folding jaw cylinder, wherein the folding jaw shafts are synchronized by means of gear wheels.
EP 0 095 605 A2 shows a control for a folding jaw of a jaw cylinder in the folding apparatus of rotary printing presses. Here, the angular position between the folding jaw and the associated roller lever can be changed.
The object of the invention is based on providing a device for setting the clamping gaps between pairs of folding jaws of a folding jaw cylinder.
In accordance with the invention, this object is attained clamping gap by the same amount of the insertion of the folding blade. Since transverse folding takes place in two stages, pre-folding and finished folding, the forces respectively required for one folding step are reduced. The lateral faces of the pre-fold product, which are in contact with the pre-fold clamping gap are handled free of damage because of the employment of cylindrical pre-fold clamping elements of the pre-fold clamping system which are operating in a pincer-like manner. In the same way the finished folding of the pre-folded product of up to 192 pages takes place free of damage because of the employment of folding rollers.
By producing a device for adjusting the clamping gap between folding jaws in accordance with the present invention, the prior art arrangement of expensive cylinder body elements, which can be rotated in respect to each other, is avoided. The distance between folding jaws can be preset by means of a simple gear.
Moreover, the device of the present invention is also suitable for pre-setting pairs of pre-fold clamping elements located on a pre-fold cylinder.